Manley Performance EJ257 Subaru WRX STI Standard Stroke Piston and Ring Set – 99.55mm Bore, 8.5:1 Compression Ratio

Description

The Manley Performance EJ257 Subaru WRX STI piston set is engineered for high-performance applications, combining durability with power. Crafted from premium 2618 alloy forgings, these pistons provide exceptional strength and reliability under demanding conditions. The design features proven cam and barrel profiles that optimize power output while minimizing stress on the cylinder walls, making them suitable for both everyday driving and serious tuning projects.
The set includes chrome moly wrist pins as standard, with options for upgrading to 9310 or Turbo Tuff/DLC alloys for enhanced durability in high-stress environments. The pistons also incorporate precisely machined ring lands and grooves, which ensure a superior ring seal for increased compression and overall engine efficiency. The unique fixturing process used during manufacturing guarantees accurate ring groove to skirt squareness and allows for efficient skirt turning and ring groove machining in a single operation, ensuring consistent quality and performance.
Designed specifically for the EJ257 engine with a bore of approximately 3.91 inches and a stroke of about 4.13 inches, these pistons are ideal for builders seeking reliable components for turbocharged Subaru engines. Their 8.5:1 compression ratio makes them suitable for a variety of tuning setups, providing a good balance of performance and longevity. The set is not carb approved but is engineered to meet high standards for automotive use, with Prop 65 compliance ensuring safety and environmental considerations. Whether upgrading an existing engine or building a new one from scratch, these pistons deliver the strength and precision needed for competitive motorsports or high-performance street applications.

Features:

• 2618 alloy forgings for superior strength and performance

• Chrome moly wrist pins as standard with upgrade options for 9310 or Turbo Tuff/DLC alloys

• Exacting ring lands and grooves for enhanced ring seal and power

• Cam and barrel profiles designed for optimal power output and cylinder wall protection

• Unique fixturing for precise ring groove to skirt squareness and efficient machining